Game crashing on iOS after 3 second load of new scene. (How can I optimise loading)

Hi guys, my game is crashing when I load between certain scenes on an iOS device . Here is a couple screenshots of the output from the Unity profiler showing the spikes.

This first one is from a main menu screen with an OnGUI function to another menu scene with an OnGUI function, so there are only textures in the gui and a 3d model of a character:

http://cl.ly/1Q2V1t443H2S2R1z3915

This second one is from that second menu scene to a large level with many objects:

http://cl.ly/2N1H2y0a0u27222a381c

What are the sort of the optimisations I need to be doing in order to reduce this and eliminate the crashing? This has only started happening recently, since I upgraded to 3.4 (perhaps this is to do with it?) Also my texture memory spikes at around 35mb for the single loading frame. Although all my textures are 256*256 pixels with a couple being 512px (all compressed and pvrtc 4 bits)

Thanks for any help you can provide me with!

Current Unity Forums thread; http://forum.unity3d.com/threads/99338-Game-crashing-on-iOS-after-3-second-load-of-new-scene.-(How-can-I-optimise-loading)?p=650083#post650083